Optical spectacles, also known as eyeglasses, may include a frame supporting a pair of ophthalmic lenses.
Optical attributes, e.g. diopter values, of the lenses may be fitted, e.g., by an optometrist, to an intended user of the spectacles. For example, the optical attributes of the lenses may be fitted according to a determined impairment in the eyesight of the user.
The spectacle frame may have one of several different sizes and/or shapes. The size and/or shape of the spectacle frame may affect the horizontal positioning of the optical lens relative to the eyes of the user. Accordingly, the lens may be designed such that a vertex of the lens may be located based on a measured distance between the pupils of the user.